Abstract

BoLA-DRB3 is a part of the major histocompatibility complex characterized by more than 100 polymorphic sites within the exon 2. This gene is associated with immunological traits and resistance or susceptibility to various diseases as well as with productive traits and milk quality in cattle. The purpose of the study was a primary evaluation of the allelic polymorphism in BoLA-DRB3 exon 2 in the Ural region using nested PCR and RFLP-PCR. The objects of the study were Holstein cows (n = 55). Restriction fragment lengths were determined by the agarose gel electrophoresis. According to the BoLA-DRB3.2 genotyping, the most common genotypes were *23/*24, *24/*24, *16/*16, *24/*28, and *9/*38 (distribution frequency from 8.9 to 26.5%); other genotypes (*24/*38, *24/*9, *2/*37, *16/*26) were characterized by a lower distribution frequency. The majority of identified alleles (*2, *9, *26, *37, *38) in the studied sampling were earlier proven to be neutral. In the studied population, the genomes associated with the susceptibility or resistance to the leukemia virus were revealed in 56 and 29% of animals, respectively; 15% of animals were characterized by a neutral genotype. Based on these results, one can conclude about the necessity of genetic screening of cattle populations for the BoLA-DRB3 polymorphism, especially in regions that are epidemiologically unfavorable in relation to leukemia. The obtained data can be used in breeding programs to enrich cattle herds with alleles associated with the resistance to the bovine leukemia virus.

中文翻译：

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使用 RFLP-PCR 评估 BoLA-DRB3 外显子 2 等位基因多态性变异体的分布频率

摘要

BoLA-DRB3是主要组织相容性复合体的一部分，其特征是外显子 2 内有 100 多个多态性位点。该基因与牛的免疫特性和对各种疾病的抵抗力或易感性以及生产性状和牛奶质量相关。本研究的目的是使用巢式 PCR 和 RFLP-PCR 对乌拉尔地区BoLA-DRB3外显子 2 的等位基因多态性进行初步评估。研究对象是荷斯坦奶牛（n = 55）。通过琼脂糖凝胶电泳确定限制性片段长度。根据BoLA-DRB3.2基因分型，最常见的基因型是*23/*24、*24/*24、*16/*16、*24/*28和*9/*38（分布频率从8.9至 26.5%）；其他基因型（*24/*38、*24/*9、*2/*37、*16/*26）的特征是分布频率较低。研究样本中大多数已识别的等位基因（*2、*9、*26、*37、*38）先前被证明是中性的。在研究人群中，分别有 56% 和 29% 的动物发现了与白血病病毒易感性或耐药性相关的基因组；15% 的动物具有中性基因型。基于这些结果，我们可以得出结论，有必要对牛群进行BoLA - DRB3多态性遗传筛查，特别是在流行病学上对白血病不利的地区。获得的数据可用于育种计划，以丰富牛群中与牛白血病病毒抗性相关的等位基因。